) to screen for depressive symptoms and to estimate the prevalence of depression in this particular population group. Patients with scores of 0–5 are considered normal; a score of 6–10 indicates moderate depression; and 11–15 indicates severe depression ( Fountoulakis et al., 1999 , Yesavage et al., 1982 ).
In order to quantify the presence of sleep disturbances, the Athens Insomnia Scale (AIS-8 items) was administered to all the participants. Each item of the scale is rated 0–3 (0: no problem and 3: serious problem). Scores ≥ 6 indicate diagnosis of insomnia